Avian practice tips and tricks (Proceedings)

My goal is to retire with the highest possible number of patients that have lived through treatment. This results in conservative care in many cases. This is NOT the most lucrative way to practice. It is the easiest emotionally. Medically, I believe it is usually the most sound.

In this lecture we will discuss the reasons that birds seem to "die easily". We will also cover:

     1) General approach to hemorrhage,

     2) Approach to the moribund bird,

     3) Diagnostic and treatment options and timing in the clinical ill but currently stable bird,

     4) Iatrogenic causes of injury and death in avian patients, and

     5) Specific cases and the risk/benefit of different treatment options.

First, birds hide signs of illness until late in the disease process. This makes the likelihood of disease progression to a serious or critical state prior to presentation high.

Secondly, birds present a greater risk when undergoing diagnostics, medical and/or surgical treatment, than do mammals (Note that reptiles pose a much lesser risk of fatality than do mammals).

The reason for this hierarchy is that the metabolic rate in birds is extremely high (and therefore the oxygen demand is great) – far exceeding that of mammals. Reptile requirements are even lower than mammals. One study conducted on box turtles consisted of gradual removal of the entire blood volume over a 48-hour period, while being replaced with an equal volume of isotonic solution. None of the turtles died, although recovery of normal function required supportive care.

We don't have this luxury with birds. Avian blood pressure increases up to 300% with stress. In fact, the blood pressure and rapidity of exsanguination make it unlikely that a practitioner will ever be presented with a bird whose life will be saved by immediate application of pressure to a bleeding site. Birds with this severity of hemorrhage die within seconds to minutes and are rarely presented to the animal hospital.

Most birds that become significantly weak from blood loss, become that way due to repeated attempts at hemostasis. The application of direct pressure or styptic to a blood feather, toenail, or wound and the restraint that is used to apply this, create pain and fear, respectively. This increases the blood pressure; whatever clotting has begun is subsequently disturbed, and bleeding begins again. When this is repeated several times over several hours, hypovolemia and anemia occur.

Blood pressure, rate of blood loss and oxygen demand factors are increasingly significant as the size of the bird decreases.

Approach to the bleeding bird:

     1) If the bleeding has stopped - Don't look for the source, don't mess with the clot!!

     2) Discuss with the owner the need to minimize additional hemorrhage. The bird needs to be hospitalized for at least several hours, and possibly longer.

     3) Administer midazolam @ 0.5 mg/kg, IM. Let the bird sit in a quiet, warm area. Offer water (most will drink if blood loss has been significant). When the midazolam has quieted the bird, administer warm S.C. fluids.

     4) When no further bleeding has occurred for several hours, and you believe the blood volume has been replaced, administer midazolam again if it is no longer on-board, and locate the source of the bleeding (laceration, broken blood feather, area of mutilation, etc). Treatment then will depend on the condition of the bird, and the source of the hemorrhage. Often, no further treatment is required.

The moribund, minimally responsive bird

Immediate emergency treatment:

     1) Slide bird and cage into warm, humidified, oxygenated environment – and that's it folks....

          a. Warm, because hypothermia is very common and under-diagnosed. (What is the normal body temperature of an African Gray or Amazon parrot?)

          b. Humidified, since dehydration and hypovolemia are common

          c. Oxygenated because, well, duh..

     2) Talk to the owner; a thorough history will narrow your differential diagnoses

     3) If the bird is minimally responsive, palpation of the keel and sterno-pubic area, without moving the bird may be accomplished.

          a. Emaciation indicates chronicity

          b. Increased sterno-pubic distance (abdominal distention) narrows differential diagnoses.

          c. In the absence of these findings, more acute disease is likely.

          d. Place the bird back into oxygen (praying doesn't hurt...)

          e. Back to the owner - collect a more thorough anamnesis to further limit the differential diagnoses.

The clinically ill but compensated bird presents:

     1) Fluffed with a weak grip at rest.

     2) Temporarily responds to stimulation by smoothing feathers and looking alert.

     3) Can't maintain this posture, returns to being sleepy and fluffed.

     4) Hot feet, hot beak often = septicemia

     5) The owner is less likely to realize the severity of its condition than they would with a moribund bird.

     6) You are less likely to be able to accomplish a PE without stressing the bird.

Hospitalization of these birds:

     • Don't forget readily accessible food and water!!

     • (Lack of these may be the initial cause of illness)

     • Remove perches/perchable surfaces

     • (Sick bird may sit perched without the energy to access food and water)

     • Offer millet spray

Interim therapy for these birds

     1) Chelating agent I.M. for heavy metal – CaEDTA @ 40 mg/kg IM.

     2) Antibiotic IM (TMS) without removing patient from enclosure if possible.

     3) Evaluate tolerance for injections and allow bird to re-oxygenate.

     4) Subq fluids (@30 ml/kg) again without removing patient. Warm fluids.... Consider IO/IV Catheter

     5) DO NOT crop feed until rehydrated.

     6) Can use 2.5% dextrose/NaCl subq if hyaluronidase is added (@ 100 I.U./liter fluid)

     7) Complete your physical examination

Good time for the 'put it down' list

     • If panting and open mouth breathing persist..

     • If releasing the head does not cause the bird to attempt to bite..

     • If the bird does not bite at a towel placed in its mouth..

     • If the bird's grip with both feet is not strong..

     • If the eyes close during the examination..

     • To be safe - "Put It Down!' and observe!

Iatrogenic causes of injury or death:

     1) Eaten by dog or cat

     2) Toe cut off in scale

     3) Leg broken while removing band

     4) Clips to keep doors closed removed (see 1 above)

     5) Application of an E. collar without sedation and close observation. Immediate problem – flip out and stress out. Also need to ensure that they are able to access food and water, and that the collar is not abrading the wings.

     6) Crop feeder trauma: If you don't trust a person to catheterize a male tomcat – the same tissue touch is needed for crop feeding. (i.e. just because one is a doctor doesn't mean they are able to do this procedure safely...)

Surgical or medical Rx? (cases will be presented in the lecture)