TOXIC FOODS – RABBITS & PARROTS

Toxic foods and common household products

Even within the safety of our own homes, there are hazards to all our pets- particularly when our pets are free-roaming such as house rabbits or pet birds. Tortoises often have free access to large areas of the garden, and so ornamental and kitchen gardens can be the source of hazardous or toxic plants.

For birds in particular, the kitchen is of most concern. It is important to consider that birds will also be at risk when flying- so removing objects to a height may be an effective option with cats and dogs but will not be enough with birds. Electrical wiring, heat sources such as irons and cooking all provide a risk to birds.

FOODS

Apple and pear seeds

The seeds or pits contained within apples, pears, apricots and plums contain amygdalin, a glycoside that degrades to release hydrogen cyanide. In reality the toxic dose in dogs, cats, rabbits and parrots is greater than they are likely to ever consume. The seeds also need to be ground into a powder to release the glycoside which is unlikely following normal mastication and digestion. Seeds tend to pass through complete.
It is recommended to remove the core when offering apple to pets, but the risk of toxicity with accidental consumption is extremely low.
Rabbits and parrots show no toxic effects with other fruits such as grapes and regularly enjoy small portions of raisins as a treat.

Avocados

Avocados are toxic to most animals- including rabbits, tortoises and parrots (1). The fungicidal compound persin is found in varying concentrations in the leaves, bark, pit and fruit. Large quantities would need to be consumed in order to cause symptoms with the exception of birds, which are known to be much more sensitive. Symptoms seen after consumption include vomiting, diarrhea, dysrhythmias and respiratory distress.

Chocolate and caffeine

Caffeine and theobromine are methylxanthines found in chocolate which can be toxic to rabbits and parrots and should be avoided in all these species in any amounts (1)(5). Dark chocolate tends to contain more theobromine than milk chocolate.
Clinical signs include excessive thirst, diarrhea, tachycardia, tremors and seziures and if untreated, toxicity can lead to cardiac arrest.

Xylitol

Is an artificial sweetener found in baked goods, candy and chewing gum and can cause release of endogenous insulin due to hypoglycaemia. Clinical signs following ingestion can be noted as soon as 30 minutes after ingestion and include vomiting, ataxia, depression and seizures. Xylitol toxicity has only been reported in dogs but should be considered toxic to all other species (1).

Onions and garlic

The allium family is extensive and includes onion, garlic, shallots, chives and leeks as well as ornamental plants such as daffodils. All forms can be toxic- cooked, raw, dried or powdered as they all contain thiosulphate (1).
Excessive ingestion will cause toxicity in dogs, cats, rabbits and parrots. Ingestion causes general gastrointestinal irritation, resulting in inflammation in the mouth, oesophagus and crop. Oxidative damage to red blood cells occurs and the resulting haemolytic anaemia will lead to weakness and fatigue. Clinical signs include lethargy, red discoloration of urine, tachycardia, ataxia and panting. Collapse and syncopal episodes may also be the reason for presentation to the clinic. In severe cases, transfusions may be necessary.

DISINFECTANTS AND CLEANING AGENTS AND MEDICATIONS

Dettol

The active ingredient in Dettol is phenol chloroxylenol and is dangerous to all animals if ingested. Commonly pets will lick the product off their paws if used within the home, rather than direct ingestion. Clinical signs include hypersalivation, ulceration to the mucous membranes, anorexia and organ failure.
Make sure that the cleaning agents used for toys, cages and enclosures are suitable and safe for contact with animals.

Human medications should never be given to animals without prior discussion with the veterinarian.

FLOWERS AND HOUSEHOLD PLANTS

For pets that have access to the garden such as rabbits and tortoises, there are several plants and flowers that may be hazardous. These include daffodils (narcissus pseudonarcissus), lilies and foxgloves (digitalis sp) (7). Citrus and avocado trees should also be monitored as the fruit, bark and leaves can be irritant. A good reference guide for tortoise owners can be found at the Tortoise Table (8).

Species specific toxins

Rabbits

Rhubarb or Rheum rhabarbarum leaves contain soluble calcium oxalate crystals and oxalic acid. Ingestion in large enough quantities will result in hypocalcaemia and irritation in the mouth, diarrhea and abdominal discomfort (3). Dogs and cats rarely eat the leaves due to their bitter taste, but rabbits may be tempted, so access to the plants should be restricted.
Iceburg lettuce should not be fed to rabbits as it contains lactucarium which can be harmful in large quantities (2).
Apple and pear tree branches are safe and recommended for chewing to promote dental health but the bark and twigs from cherry trees should be avoided.

Parrots

In pet birds, heavy metal toxicosis (lead or zinc) is often the result of ingestion- from metal blinds, lead paint, toys, keys, mirror frames etc (5)(6). Once ingested, the metal degrades in the ventriculus and is slowly released into the gastrointestinal tract and bloodstream. Clinical signs of lead toxicity include anorexia, weight loss, decreased mentation, ataxia, polyuria and polydipsia. Neurological signs may progress to seizures and blindness and in certain species, haemaglobinuria will be a sign (4)(6). Zinc toxicosis presents very similarly but without neurological symptoms.
Diagnosis is based on clinical signs and biochemical analysis and metal levels detected in the blood. When suspicious of zinc toxicosis, the blood must be collected in full plastic or glass tubes- rubber stoppers can artificially increase the amount of zinc in the samples.
Radiographs may also reveal metallic deposits within the GI tract.
Treatment with supportive care- intravenous fluid therapy and chelation with calcium edetate disodium (Ca EDTA) 30-35mg/kg SC or IM for 3-5 days until asymptomatic. Midazolam or diazepam may be necessary for the control of seizures in case of lead toxicosis.

Polytetrafluoroethylene (PTFE) or Teflon is a synthetic polymer used as a non-stick surface in cookware (4). PTFE cookware is perfectly safe when used at normal cooking temperatures, however when heated to beyond 530^oF or 275^oC, toxic gases are released from the equipment. Birds are very very sensitive to the fumes and inhalation will prove fatal very quickly (4)(6), particularly in smaller birds. Clinical signs include dyspnea, wheezing and ataxia.
Supportive therapy with a warm oxygenated incubator, fluids and NSAIDs may be provided but the prognosis is guarded. Humans, dogs and cats are much less sensitive. Birds are recommended not be housed anywhere near kitchens, in case of misuse of equipment.

Passive smoking can be irritant to parrots (6). Contact both via secondary inhalation and with tobacco on hands/clothes can lead to chronic respiratory and dermatological disease. Ocular and nasal discharge, conjunctivitis, coughing and sneezing can all be seen as a result of exposure. Treatment will vary depending on the nature of clinical signs and severity. Owners who smoke are advised to be cautious and wash hands/change clothes before handling their pet bird.

This list is not exhaustive and is aimed to provide concise information and where possible, direct clinicians to further appropriate references.
It is always safest to request the owner presents their animal to the vet as soon as toxicity is suspected, particularly if gastric lavage and decontamination may be an option. Photographs of the plants or packaging of food stuffs and pharmaceuticals will also be extremely helpful to the clinician.

Often the clinical signs can mimic heat stroke, dietary indiscretion or epilepsy, and a detailed history may be required to investigate- but the sooner the animal is presented to the clinic, the quicker the appropriate intervention can begin.

Reference:

Postdate: 29th Nov 2020

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